KANSAS CITY, Mo. – Three days in a row now Kansas City has set new heat index records.
Monday’s peak heat index hit 119 degrees, breaking Sunday’s record of 118 degrees, which broke Saturday’s tied record of 117 degrees.
Air temperatures though over the last several days have been nowhere near record levels, so how are we setting record heat index values? The extreme humidity.
The Heat Index isn’t a new number for meteorologists or avid weather watchers. It has been in use since 1979. It is a combination of the air temperature and relative humidity, which is determined from the dew point.
So it easily reasons that record setting dew points would help create near record if not record heat index numbers.
Dryer air typically heats up faster because of a lower specific heat content. That’s because water molecules (present in more humid air) require more energy to heat up when compared to a completely dry air mass.
That’s why the record high air temperature of 113° in Kansas City from 1936 didn’t result in a record heat index.
An Excessive Heat Warning continues for the Kansas City metro through Thursday, with daily heat index values expected over 110° and high air temperatures in the upper 90s.
Stay with the FOX4 Weather Team for updated forecasts as they track when more seasonable temperatures return to the Midwest.